Disazo dyestuffs



United States Patent Ice meme. aiiifiiii I illustrating the invention, without, however, limiting it 2,886,562 thereto. V

' Example 1 DISAZO DYESTUFFS 27.2 g. (0.1 mol) of 44-dia.mino-3 3-dicarboxy-di 5 I t; ilii'fitrfifihli' i?al'fii;gie'1fi$=ia ?v'35 e ge a P 5 2; ga -g e G 0 Mia f Germa w1 g. 0 so 1um mtrite an o y roc OIIC kusen ac i Hy acid. To the tetrazo salt solution there is added an No Drawing. Appl1cat1on June 1956 aqueous suspension of 30.3 g. (0.1 mol) of 1-(8'-sulfosenal 594,700 2'-naphthyl)-3-methyl-5-aminopyrazol; the reaction mix Cl licafion German Au st 11 1955 ture is adjusted to a pH-value of 8 to 9 by addition of aims pm y sodium bicarbonate. The dark half-sided coupling prod- 3 ClalmS- uct soon precipitates. It is isolated as soon as no tetrazo I compound can be detected any longer. The diazo mono- The present invention relates to disazo dyestuifs and 15 azo dyestuif thus obtained is mixed within 12 hours with to a process for their manufacture; more particularly, it v 31.5 g. (0.1 mol) of 2-phenylamino-S-hydroxy-naphthalrelates to disazo dyestuifs of the following formula: ene-G-sulfonic acid in 1000 ml. of ice-water and 50 g. of

CH CCN=N N=N NHR1 1L5'\ /i' -NH2 00H N H0O I HOaS R wherein R stands for an aryl radical and R means hysoda. The reaction mixture is then heated to 50 C. and drogen, alkyl or aryl. the disazo dyestuflz' of the following formula:

CH,-CCN=N N=N NH-O 1L5 Hg 0 OH I I N H0O H0 8 soar! It is an object of the present invention to provide new is isolated. It dyes cotton and regenerated cellulose in disazo dyestufis of good fastness properties. It is u a dark brown shades, which become fast to light and washfurther object to provide new disazo dyestuifs which can 'ing by treatment with copper salts. be treated with copper salts. Dyestufls of similar dyeing properties are obtained if,

The new disazo dyestulfs are obtainable by coupling instead of l-(8'-sulfo-2'-naphthyl)-3-methyl-5-aminopy tetrazotized 4,4'-diamino-3,3'dicarboxy-diphenyl with 1 razol, equivalent parts of 1-(3-sulf0-1'-phenyl)-3-methylmol of a l-aryl-3-methyl5-aminopyrazol which may be S-amino-pyrazol, 1 (4' su1fo-l'-phenyl) 3 methyl-5- substituted in the aryl nucleus e.g. by' sulfonic or car aminopyrazol or the aminopyrazol of chloroanilineboxylic acid groups and combining the diazo-monoazo' 'mono-sulfonic acid or the aminopyrazol of 4-aminodyestuff thus obtained with Z-arnino-8-hydroXy-naphthal- H benzoic acid are-used; Instead of 2-phenyl-amino-8-hyene-6-sulfonic acid or its N-alkyl 'or N-aryl-derivatives. droxynaphthalene-fi-sulfonic acid, 2-methylamino-, 2-p- The resultant diazo dyestuifs can be converted into their tolylaminoor 2-p-anisidylamino-8-hydroxy-naphthalenecopper complexes by after-treatment with copper salts. 6-sulfonic acid can also be used as azo compounds.

The dyestuffs dissolve in water with dark brown coloration and yield dark brown dyeings on cotton and regener- E l 2 ated cellulose, which become fast to light and washing by after-treatment with copper salts. 27.2. g. (0.1 mol) of 4,4'-diarnino-3,3'-dicarboxy-di- The following examples are given for the purpose of phenyl are tetrazotized in usual manner in 500 ml. of

3 ice-Water with 13.8 g. of sodium nitrite and 55 ml. of hydrochloric acid. Into this solution there are introduced 17.3 g. (0.1 mol) of l-phenyl-3-methyl-5-aminopyrazol which is dissolved in 200 ml. of water and 15 ml. of hydrochloric acid. The solution is neutralized 5 and dyes cotton and regenerated cellulose in red-brown shades which become fast to light and washing by treatment with after-salts.

I claim:

1. A disazo dyestuff corresponding to the formula:

at C. with aqueous sodium acetate solution to a wherein R stands for a member selected from the group pH-value of 4-5 and stirred with coolinguntil the tetrazo compound cannot be detected any longer. The isolated diazo-azo compound is added to a solution of 48.6 g. (0.1 mol) of 2-(4-amino-3'-sulfodiphenylarnino)-8-hydroxy-naphthalene-6-su1fonic acid in, 1500 ml. of icewater and 100 g. of soda. The mixture is stirred over night, then heated to C. and the disazo dyestuif is N icol isolated. It corresponds to the formula:

consisting of radicals of the benzene and naphthalene series and R means a member selected from the group consisting of hydrogen, lower alkyl and a benzene radical containing a single benzene nucleus and a diphenyl 2O radical.

2. The disazo dyestufi corresponding to the formula:

3. The disazo dyestuff corresponding to the formula:

soarr CH -C--C-N=N N=N- -NH NH, k (IL-NH i]: so E N/ H00 3 References Cited in the file of this patent UNITED STATES PATENTS 2,241,796 T aube et al May 13, 1941. 2,384,419 Fleischhauer et a1. Sept. 4, 1945 2,426,977 Straub et al Sept. 9, 1947 FOREIGN PATENTS 745,461 German Mar; 13', I944 

1. A DISAZO DYESTUFF CORRESPONDING TO THE FORMULA: 